Method for Monitoring an Injection Fluid Quantity and Injection System for Injecting an Injection Fluid Quantity

Abstract

A method for monitoring an injection fluid quantity, which is injected through an injection nozzle, includes opening and closing said injection nozzle by a closure element guided in one movement, detecting at least three characteristic points of the movement of the closure element at which the closure element is located at a certain position, and calculating the injection quantity from the at least three detected characteristic points.

What is claimed is: 
     
         1 . A method for monitoring an injection quantity of a fluid which is injected through an injection nozzle, comprising:
 opening and closing the injection nozzle using a closing element which is guided in a movement,   detecting at least three characteristic points of the movement at which the closure element is situated at a certain position of the movement, and   calculating the injection quantity based on the at least three detected characteristic points.   
     
     
         2 . The method of  claim 1 , comprising detecting four characteristic points of the movement. 
     
     
         3 . The method of  claim 1 , wherein:
 the closure element is guided in a lifting movement between a closed position and a lifted position, and   at least one of the characteristic points comprises at least one of:
 a starting point of an opening movement at which the closure element departs from the closed position for the purpose of opening the injection nozzle; 
 an end point of the opening movement at which the closure element reaches the lifted position; 
 a starting point of the closing movement at which the closure element departs from the lifted position for the purpose of closing; and 
   an end point of a closing movement at which the closure element reaches the closed position for the purpose of closing the injection nozzle.   
     
     
         4 . The method of  claim 1 , wherein:
 calculating the injection quantity comprises determining, in a characteristic map of an injection rate, an area enclosed between an axis of the characteristic map and a curve, and   coordinates of the curve in the characteristic map are defined by the characteristic points and by the injection rates corresponding to the respective characteristic points.   
     
     
         5 . The method of  claim 1 , wherein the closure element is guided in the movement by means of a drive device, and wherein a signal of the drive device is used for the determination of the characteristic points. 
     
     
         6 . The method of  claim 5 , wherein the signal comprises at least one of a capacitance, a voltage, a change in capacitance, and a change in voltage of the drive device. 
     
     
         7 . The method of  claim 1 , wherein the control device actuates the closure element such that at least one of the characteristic points coincides with a predefined target value. 
     
     
         8 . An injection system for the injection of an injection quantity of a fluid, comprising:
 a control device, and   at least one injection nozzle, each injection nozzle has comprising:
 a closure element for closing and opening the injection nozzle, 
 a drive device for guiding the closure element in a movement, and 
 a sensor for detecting positions of the closure element, 
 wherein the sensor is configured to detect at least three characteristic points of the movement at which the closure element is situated at a certain position of the movement, and 
   a processing unit configured to calculate the injection quantity from the at least three detected characteristic points.   
     
     
         9 . The injection system of  claim 8 , wherein:
 the sensor is configured to detect four characteristic points of the movement,   the closure element is guided between a closed position and a lifted position in a lifting movement, and   the sensor is configured such that at least one of the characteristic points comprises at least one of:
 a starting point of an opening movement at which the closure element departs from the closed position for the purpose of opening the injection nozzle; 
 an end point of the opening movement at which the closure element reaches the lifted position; 
 a starting point of the closing movement at which the closure element departs from the lifted position for the purpose of closing; and 
 an end point of a closing movement at which the closure element reaches the closed position for the purpose of closing the injection nozzle. 
   
     
     
         10 . The injection system of  claim 8 , wherein the processing unit is configured to calculate the injection quantity from an area enclosed, in a characteristic map of an injection rate, between an axis and a curve, wherein coordinates of the curve in the characteristic map are defined by the characteristic points and by injection rates corresponding to the respective characteristic points. 
     
     
         11 . The injection system of  claim 8 , wherein the sensor is configured to detect at least one of the characteristic points on the basis of a signal of the drive device and to transmit said signal to the control device. 
     
     
         12 . The injection system as of  claim 11 , wherein the signal comprises a capacitance, a voltage, a change in capacitance or a change in voltage. 
     
     
         13 . The injection system of  claim 8 , wherein the processing unit is configured to transmit a control signal to the control unit as a function of one of the detected points such that said control unit actuates the closure element such that, during a further run-through of the movement, the detected point coincides with a predefined characteristic point. 
     
     
         14 . The injection system of  claim 8 , wherein the drive device has a piezo actuator. 
     
     
         15 . The injection system of  claim 8 , wherein the closure element has a nozzle needle.